A pair of strong aluminium clamps, which allows strip material to be investigated for breaking strain, stretch etc. The clamps have wing-nut fixings and an attachment system which ensures freedom from slip. These clamps are used to study the comparison of the strengths of bag materials, stretching of fabrics, stretching of plastics and newspaper strength. This is done by attaching one of the clamps to the clamp provided in the laboratory and loading the lower clamp with slotted weights. A maximum of 15kg of weight can be hanged.